Inflatable structures are constructed from sheets and strips of thermoplastic covered fabrics sewn and fused together to form the walls and sections of the structure, which are then inflated by fans and blowers. The cavity between the layers of fabric is pressurized with air to produce a rigid structural element. Sewn joints and seams of all inflatable structures leak or “bleed” air. High-volume fans or blowers replace the air that is bled through the sewn seams.
Inflatable structures use internal spars and baffles of the thermoplastic fabric used to provide additional structural integrity. Typically, spars and baffles extend between two main wall panels of the structure and are sewn or heat fused to those panels. Heretofore, internal spars and baffles are joined between two wall panels using what is commonly referred to as a “T-Weld.” FIGS. 1 and 2 illustrate a conventional T-weld. As shown, a T-weld consists of strips of PVC fabric that extends the length of the spar or baffle and is heat welded to the wall panel. These strips are folded into an “L” shape and positioned opposed to one another—back to back. The adjacent backs of the strips are heat welded together forming the “T” shape element with the extending legs, which are heat welded directly to the wall panel. The internal spar or baffle is sewn or welded directly to either side of the fused backs of the two strips.
While useful in most applications, the use of T-welds produces a “pillowed” surface in the main wall panels. While the T-weld securely connects the spar or baffle to the main wall panel, the L-shaped strips that form the T-weld do not prevent the main wall panel from bowing outward when the structure is inflated, as shown in FIG. 2. As a result the wall panel generates an undulating external surface. In many applications, such as for slide lanes of an inflatable slide, a more flat and “seamless” external surface is desirable.